running 240v power tools off inverter attached to car battery

I have an inverter on my boat that I, occasionally, use to run power tools. Mine is a 3000 watt and it runs off 3 leisure batteries. it's okay for short usage but I couldn't/wouldn't use it for any prolonged power tool usage. I also use mine with the boat engine running on a fast tickover. I still wouldn't use it for any prolonged work. Your car starter battery is designed for big power transfer for short bursts i.e. when running the starter motor, not for any prolonged powering of a device such as an inverter. I think it would quite quickly run your car battery down.
 
say your drill is 1000w call it an average 500w over a cycle
a 32ah car battery contains 12x32=384w allow for say 20% losses that gives 310w so about 35-40 mins work
 
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Plus the waveform from some of the cheapo inverters is a bit rubbish- any speed control devices likely won't work properly. Cordless tools or a gennie will be best bet
 
Inverters are ok, fitted one on a van before, even with big cables things can still get hot when you're using a lot of power. For the money you could probably get a 2nd hand generator
 
just noticed you say "with engine running "
delicate electronics in a car more in the inverter and also in the tool may cause havoc or damage ??
 
Bear in mind that running a 500w drill will be pulling around 50amps on the dc side, the startup load will probably be higher....
 
Also your van insurance would be invalid if the engine is running and you are not in control of the vehicle.

Andy
 
Slight derail- how do ice cream vans work then? Is there a 'parked' gear that just runs an alternator (or compressor for all i know) cos they're parked up with engine running......
 
oldbutnotdead said:
Slight derail- how do ice cream vans work then? Is there a 'parked' gear that just runs an alternator (or compressor for all i know) cos they're parked up with engine running......
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Don't know about the legalities of it, but on some vehicles that are left with the engine running there is a "run lock" system, which allows you to take the keys out (with the engine going) but if you release the handbrake, touch brake/clutch pedal etc it will cut out
 
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